The invention relates to adjustment mechanisms for vehicle seats, and more particularly to a recliner assembly for vehicle seats.
Seat reclining mechanisms, of a Taumel design, include an inner gear partially engaged with an outer gear that has a smaller number of teeth than the inner gear. In such a design, eccentric movement of the gears generally eliminates rattling associated with circular movement of gears when the inclination of the seat back is adjusted.
Generally, Taumel type recliner assemblies include a pair of plates having the inner and outer gears described above formed thereon. The plates are positioned on top of each other such that the inner and outer gears engage each other to provide movement to a seat back relative to a seat cushion. Typically, a friction clutch type mechanism including wedge members that are releasably engaged with the inner and outer gear plates is utilized. Such a clutch mechanism locks the seat back in position when adjustment is not being performed, and then releasably moves with the plates when an adjustment operation is underway.
The friction clutch or wedge type adjustment mechanisms of the prior art have limitations including a lag in response time when reversing the direction of adjustment. There is therefore a need in the art for a recliner adjustment mechanism that has a quick response time when reversing the direction of rotation of a recliner mechanism such that a passenger of a motor vehicle does not perceive an extended lag or pause in the adjustment of a seat assembly. Additionally, such a recliner mechanism should have a low cost design and meet the packaging demands required for seat mechanisms.